水热合成勃姆石纳米棒及其改性复合膜  

Hydrothermal Synthesis of Boehmite Nanorods and Characterization of Boehmite Nanorods Coated Separator

作　　者：罗传鹏 袁双龙[1] 李红波[1] 杨云霞[1] 袁晓[1] 柳翠[1] 叶晓军[1] LUO Chuanpeng;YUAN Shuanglong;LI Hongbo;YANG Yunxia;YUAN Xiao;LIU Cui;YE Xiaojun(School of Materials Science and Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学材料科学与工程学院,上海200237

出　　处：《材料科学与工程学报》2021年第2期264-270,共7页Journal of Materials Science and Engineering

摘　　要：商用锂离子电池隔膜遭受高温时,会发生热收缩现象,通过涂覆无机颗粒对隔膜进行改性,可以有效地提高隔膜的热稳定性能,从而提高锂离子电池的安全性能,而勃姆石纳米棒具有耐热性好和弹性模量大等特点,适用于涂覆改性隔膜。本研究利用AlCl_(3)和NaOH与NH_(4)OH混合沉淀剂,通过水热法制备了勃姆石纳米棒,并使用线棒涂布工艺制备了涂覆复合膜,显著提高了隔膜的热稳定性能。通过扫描电子显微镜(SEM)与X射线衍射仪(XRD)研究了pH值、沉淀剂配比、保温时间和水热温度等对产物形貌的影响。研究结果表明,当pH值升高时,勃姆石纳米棒长度减小,直径增大;当增加NH_(4)OH的体积比时,水热产物长度减小,直径增大,但分散更加均匀,典型的水热产物长度为200-400nm,直径为40-50nm,且涂覆复合膜具有良好的热稳定性,150℃下热处理0.5h后尺寸收缩小于5%。因此,利用水热法成功制备的符合隔膜涂覆改性的勃姆石纳米棒具有应用前景。Thermal shrinkage of the commercial separator in a lithium ion battery at high temperatures has aroused wide attentions.To gain enhanced thermal stability,inorganic particles have been employed to coat the lithium ion battery separator.Boehmite nanorods are expected to a be good candidate for the coating due to excellent heat resistance and high elasticity modulus.The boehmite nanorods were synthesized via a facile hydrothermal route by using AlCl_(3) as raw material and NaOH and NH_(4)OH as mixed precipitant.Coating of the separator by the nanorods was realized by roll coating process.This process has demonstrated to reduce the thermal shrinkage of the separator.The effects of pH values,molar ratio of the mixed precipitant,reaction time and hydrothermal temperature on the morphologies of the products were examined by scanning eletron microscope(SEM)and X-ray diffraction(XRD).The length of boehmite nanorods decreased and the diameter increased with increasing pH value or increasing volume ratio of NH_(4)OH.The products were dispersed more uniformly as the volume ratio was higher.The lengths and diameters of typical products were 200-400 nm and 40-50 nm,respectively.The boehmite nanorods coated separators exhibited excellent thermal stability,and the shrinkage was reduced to less than 5%after exposure at 150℃ for 0.5 h.Therefore,boehmite nanorods synthesized via a hydrothermal route provide a promising alternative coating material for composite separator.

关 键 词：水热法 勃姆石 涂覆复合膜 热稳定性能 

分 类 号：TB383[一般工业技术—材料科学与工程]